Softwares like Graph Pad Prism and Origin could help you to fit data of VO2 kinetics. Depends on the intensity (domain) you need to fit using a monoexponencial (moderate) or biexponetial (heavy and severe) equations. Using these equations you will find MRT and/or tau and/or t1/2 and TD. There are many concerns about VO2 kinetics such as exclude or not cardiodynamic phase, fixed the onset at time zero etc....

Thanks for your suggestions, Ricardo de Lucas. It's really helpful and useful. Yes, the fitting curves or equations relate with the exercise intensities. And the cardiodynamic phase (phase I) is also needed to be carefully considered. And it depends on the purpose of study. I will try to use these software to analyze our data. Thanks again.

I would agree that Graph-pad is suitable. However we have written a sampling/smoothing macro in excel that fits and analyses all three phases. Happy to let you have a copy.

Thanks for your responses. I would very appreciate to get one copy of excel file. There should be many ways to calculate these data. But, for developing the practical application in the sports field, which one would be the easiest way?

We have tried many different approaches. The excel method is easy to use although there is a degree of trial and error. However reliability is very good. We have published in Int J Sports Med using this approach.

One place you might want to look is in the anesthesiology literature. Since one of their first jobs is to understand oxygen delivery to the various tissues they have lots of models (some of them actually quite good) to describe such things. I know this because I trained as an anesthesiologist but it has been awhile since I have practiced so I am not sure what is the current best model.

You can use SigmaPlot for the analysis of oxygen uptake kinetics.

Below steps can help you for analysis.

If you want to analyze constant load sub-maximal exercise you will do monoexponential

curve fitting

1) Analysis

2) Dynamic Fit Wizard Equation

3) Single, 3 Parameter

If you want to analyze constant load supra-maximal exercise you will do double exponential curve fitting

1) Analysis

2) Dynamic Fit Wizard Equation

3) Single, 5 Parameter

Thanks, Elvin Onarici Gungor. The SigmaPlot indeed is a very easy and friendly software to analyze the oxygen kinetics. We recently tried to use this software to analyze our O2 data. It is really easier than the Excel software to find the fitting curve. Hope we can find something new with our studies.

You could just calculate your own using SPSS? I have done this in a number of combat sports where it is not possible to directly measure VO2. It might be worth having a read of....

Article The Energetics of Semi-Contact 3 x 2 min Amateur Boxing.